[Yeah... okay. It's definitely not protocol, but it just seems silly to stand on it when there isn't a hierarchy, here. He's not going to give Sledge orders, after all, nor is he going to expect the young man to follow anything he suggests, unless he actually thinks it's a good idea.

He looks a little sheepish, but he plows right on ahead.] I just want you to realize that... yeah, we're both military - and we're not the only ones aboard - but I don't have any more authority on this boat than you do. So if you really want to keep up with the rank, I won't stop you, but I don't want you waiting for orders I don't have a lot of right to give.

[He smiles a little more genuinely, now.] Besides. You look like you could use a friend a lot more than a commanding officer.

And - [The smile's sheepish again.] If you'd still rather stand on rank, Cap's a hell of a lot shorter than Captain America.